Amplitude modulated transmitter for single sideband operation

Claim 1

In a transmitter of amplitude modulated single sideband signals, which transmitter includes an output stage having a control electrode connected to receive a single sideband input signal having an envelope curve, the output stage having a nonlinear gain characteristic and effecting substantial linear amplification of the single sideband input signal, and a reactance network tuned to the single sideband frequency and connected to the output of the output stage, the improvement wherein; said transmitter further comprises control means connected to said output stage for controlling the current conduction angle at the output of the output stage in a manner to increase the current conduction angle as the amplitude of the input signal decreases; said control means including signal conduction means for applying the single sideband input signal and a signal derived from the envelope curve of the single sideband input signal to the control electrode of said output stage without any substantial relative phase shift and in a hysteresis free manner; and said control means further including current conduction angle varying means for varying the output current conduction angle down to values corresponding to class C amplifier operation for the highest single sideband input signal amplitudes.